Acute physiological and perceptual responses to moderate intensity cycling with different levels of blood flow restriction

Abstract

The aim of this study was to compare: i) the physiological and perceptual responses of low-load exercise [(moderate intensity exercise (MI)] with different levels of blood flow restriction (BFR), and ii) MI with BFR on the bike with high intensity (HI) exercise without BFR. The protocol involved large muscle mass exercise at different levels of BFR, and this differentiates our study from others. Twenty-one moderately trained males (age: 24.6 ± 2.4 years; VO 2peak: 47.2 ± 7.0 ml . kg -1. min -1 , mean ± sd) performed one maximal graded exercise test and seven 5-min constant-load cycling bouts. Six bouts were at MI [40% peak power (P peak ), 60%VO 2peak ], one without BFR and five with different levels of BFR (40%, 50%, 60%, 70%, 80% of estimated arterial occlusion pressure). The HI bout (70%P peak, 90%VO 2peak ) was without BFR. Oxygen uptake (VO 2 ), heart rate (HR), blood lactate (BLa), rate of perceived exertion (RPE), and tissue oxygen saturation (TSI) were recorded. Regardless of pressure, HR, BLa and RPE during MI-BFR were higher compared to MI (p < 0.05, ES: moderate to very large), and TSI reduction was greater in MI-BFR than MI (p < 0.05, ES: moderate to large). The responses of VO 2 , HR, BLa, RPE and TSI induced by the different levels of BFR in MI-BFR were similar. Regardless of pressure, the responses of VO 2 , HR, BLa and RPE induced by MI-BFR were lower than HI (p < 0.05), except for TSI. TSI change was similar between MI-BFR and HI. It appears that BFR equal to 40% of arterial occlusion pressure is sufficient to reduce TSI when exercising with a large muscle mass.

The Influence on Post-Activation Potentiation Exerted by Different Degrees of Blood Flow Restriction and Multi-Levels of Activation Intensity

“…In earlier studies of BFR, evidence reported that the high-order motor unit is not only related to the force and speed of muscle contraction but is also related to oxygen concentration during exercise [ 28 ]. In addition to restricted blood flow, there was also a significant reduction in tissue oxygen saturation during BFRT [ 29 ], which is correlated to the high-order motor units. To verify this finding, relative studies were collected and analyzed in this study.…”

“…For the 70% AOP groups, only jump height increased significantly at 8 min of BFR-70-30, this means a high degree of AOP during BFR activation has little effect on PAP. Previous studies suggest that a moderate degree of AOP is better than a high degree for both strength [ 41 ] and aerobic exercise [ 29 ]. Loenneke investigated the influence of different degrees and intensities of AOP on the activation of muscle fiber, and the results showed that muscle activation increases from 40~50% AOP, but does not increase further with a higher AOP (50~60% AOP), thus showing that high degree of AOP does not greatly affect the torque [ 41 ].…”

Acute Responses in Blood Flow Restriction Low-intensity Aerobic Training: A Meta-analysis

“…3b ). After excluding two studies 28 31 , results were maintained and heterogeneity was reduced (SMD=5.22 [CI95%=4.27, 6.17]; p<0.00001; I 2 =0%).…”

“…5a). After removing three studies [10,13,31], results were maintained and heterogeneity was reduced (SMD = 1.44 [CI95 % = 1.02, 1.85]; p < 0.00001; I 2 = 0 %). Two studies (two interventions) reported sufficient data to determine the pooled effect of HIT vs. low-intensity aerobic training with BFR on session RPE (sRPE).…”

“…However, our analyses must be evaluated with a certain level of caution, as a certain level of inconsistency has been identified. By individually analyzing the effect estimates of the studies included in the meta-analysis, it is possible to identify that in some studies, the RPE was similar between the tested interventions [13] or even higher in low-intensity training with BFR [31]. The application of BFR can significantly increase the levels of muscle fatigue provided by low-intensity training [13].…”